In this study, we investigated brain mechanisms for the generation of subjective experience from objective sensory inputs. Our experimental construct was subjective tranquility. Tranquility is a mental state more likely to occur in the presence of objective sensory inputs that arise from natural features in the environment. We used functional magnetic resonance imaging to examine the neural response to scenes that were visually distinct (beach images vs. freeway images) and experienced as tranquil (beach) or non-tranquil (freeway). Both sets of scenes had the same auditory component because waves breaking on a beach and vehicles moving on a freeway can produce similar auditory spectral and temporal characteristics, perceived as a constant roar. Compared with scenes experienced as non-tranquil, we found that subjectively tranquil scenes were associated with significantly greater effective connectivity between the auditory cortex and medial prefrontal cortex, a region implicated in the evaluation of mental states. Similarly enhanced connectivity was also observed between the auditory cortex and posterior cingulate gyrus, temporoparietal cortex and thalamus. These findings demonstrate that visual context can modulate connectivity of the auditory cortex with regions implicated in the generation of subjective states. Importantly, this effect arises under conditions of identical auditory input. Hence, the same sound may be associated with different percepts reflecting varying connectivity between the auditory cortex and other brain regions. This suggests that subjective experience is more closely linked to the connectivity state of the auditory cortex than to its basic sensory inputs.

Aims. We study the generation of transversal oscillations in coronal loops represented as a straight thin flux tube under the effect of an external driver modelling the global coronal EIT wave. We investigate how the generated oscillations depend on the nature of the driver, and the type of interaction between the two systems. Methods. We consider the oscillations of a magnetic straight cylinder with fixed-ends under the influence of an external driver modelling the force due to the global EIT wave. Given the uncertainties related to the nature of EIT waves, we first approximate the driver by an oscillatory force in time and later by a shock with a finite width. Results. Results show that for a harmonic driver the dominant period in the generated oscillation belongs to the driver. Depending on the period of driver, compared to the natural periods of the loop, a mixture of standing modes harmonics can be initiated. In the case of a non-harmonic driver (modelling a shock wave), the generated oscillations in the loop are the natural periods only. The amplitude of oscillations is determined by the position of the driver along the tube. The full diagnosis of generated oscillations is achieved using simple numerical methods.

Background: Arthroscopic meniscectomy often results in rapid recovery and return to preinjury activities; however, postoperative hemarthrosis and swelling can lead to pain, decreased range of motion, and delayed return to work and leisure activities. Tranexamic acid (TXA) is a lysine-based inhibitor of plasminogen to plasmin that has gained popularity in arthroplasty surgery for reducing blood loss and, more recently, in anterior cruciate ligament reconstruction by reducing postoperative hemarthrosis, swelling, and pain while increasing function in the short term. Purpose: To determine whether there is a role for TXA in improving the short-term results of swelling, pain, and function following arthroscopic meniscectomy. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: We performed a prospective double-blinded randomized controlled trial in 41 patients undergoing arthroscopic meniscectomy by comparing patients treated with intravenous TXA with those treated with a placebo (normal saline). A single surgeon treated all patients. Following randomization, a dose of 1 g of TXA in 100 mL of normal saline (treatment group) or 100 mL of normal saline (placebo group) was given intravenously at induction prior to tourniquet inflation by the anesthetist. The anesthetist administering the TXA or placebo was not blinded, but all other clinicians involved were. Patients were evaluated by a blinded observer at postoperative days 3, 14, and 30, with the range of motion, swelling, pain levels (visual analog scale), and Lysholm and Tegner knee scores recorded. Results: Patient demographics were similar in both groups. In the treatment group, there was a nonsignificant improvement in range of motion ( P = .056) and swelling ( P = .384) at 14 days; however, there was a significant improvement in the Tegner score at 3 days ( P = .0064). The complication profile was similar between the groups. Conclusion: The administration of 1 g of intravenous TXA in routine arthroscopic meniscectomy may improve early functional recovery without increased risk. A larger study is required to confirm these results and further evaluate any potential benefit. Registration: ACTRN12618001600235 (Australian New Zealand Clinical Trials Registry).

Aims. On 13 June 1998, the TRACE satellite was fortuitously well placed to observe the effects of a flare-induced EIT wave in the corona, and its subsequent interaction with coronal magnetic loops. In this study, we use these TRACE observations to corroborate previous theoretical work, which determined the response of a coronal loop to a harmonic driver in the context of ideal magnetohydrodynamics, as well as estimate the magnetic field strength and the degree of longitudinal inhomogeneity. Methods. Loop edges are tracked, both spatially and temporally, using wavelet modulus maxima algorithms, with corresponding loop displacements from its quiescent state analysed by fitting scaled sinusoidal functions. The physical parameters of the coronal loop are subsequently determined using seismological techniques. Results. The studied coronal loop is found to oscillate with two distinct periods, 501 ± 5 s and 274 ± 7 s, which could be interpreted as belonging to the fundamental kink mode and first harmonic, or could reflect the stage of an overdriven loop. Additional scenarios for explaining the two periods are listed, each resulting in a different value of the magnetic field and the intrinsic and sub-resolution properties of the coronal loop. When assuming the periods belong to the fundamental kink mode and its first harmonic, we obtain a magnetic field strength inside the oscillating coronal loop of 2.0 ± 0.7 G. In contrast, interpreting the oscillations as a combination of the loop's natural kink frequency and a harmonic EIT wave provides a magnetic field strength of 5.8 ± 1.5 G. Using the ratio of the two periods, we find that the gravitational scale height in the loop is 73 ± 3 Mm. Conclusions. We show that the observation of two distinct periods in a coronal loop does not necessarily lead to a unique conclusion. Multiple plausible scenarios exist, suggesting that both the derived strength of the magnetic field and the sub-resolution properties of the coronal loop depend entirely on which interpretation is chosen. The interpretation of the observations in terms of a combination of the natural kink mode of the coronal loop, driven by a harmonic EIT wave seems to result in values of the magnetic field consistent with previous findings. Other interpretations, which are realistic, such as kink fundamental mode/first harmonic and the oscillations of two sub-resolution threads result in magnetic field strengths that are below the average values found before.